Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C231/00—Preparation of carboxylic acid amides
  • C07C231/12—Preparation of carboxylic acid amides by reactions not involving the formation of carboxamide groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C247/00—Compounds containing azido groups
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P9/00—Drugs for disorders of the cardiovascular system
  • A61P9/12—Antihypertensives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
  • B01J23/44—Palladium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C231/00—Preparation of carboxylic acid amides
  • C07C231/22—Separation; Purification; Stabilisation; Use of additives
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C237/00—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups
  • C07C237/48—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups having the carbon atom of at least one of the carboxamide groups bound to a carbon atom of a six-membered aromatic ring being part of a condensed ring system of the same carbon skeleton
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C243/00—Compounds containing chains of nitrogen atoms singly-bound to each other, e.g. hydrazines, triazanes
  • C07C243/24—Hydrazines having nitrogen atoms of hydrazine groups acylated by carboxylic acids
  • C07C243/38—Hydrazines having nitrogen atoms of hydrazine groups acylated by carboxylic acids with acylating carboxyl groups bound to carbon atoms of six-membered aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2602/00—Systems containing two condensed rings
  • C07C2602/02—Systems containing two condensed rings the rings having only two atoms in common
  • C07C2602/04—One of the condensed rings being a six-membered aromatic ring
  • C07C2602/10—One of the condensed rings being a six-membered aromatic ring the other ring being six-membered, e.g. tetraline

Definitions

• Aminotetralins which have dopamine-like pharmacological activity are known.
• Woodruff, Comp. Gen. Pharmacol., 2, 439 (1971) describes 2-amino-6,7-dihydroxy-1,2,3,4-tetralin (ADTN) and states that it has a dopamine-like action.
• ADTN 2-amino-6,7-dihydroxy-1,2,3,4-tetralin
• M7(2-dimethylamino-5,6-dihydroxy-1,2,3,4-tetralin) is also said to have dopamine-like activity--see Cannon et al., J. Med. Chem., 15, 348 (1972) and Long et al. J. Pharm. Exper. Therap., 192, 336 (1975). Its action parallels that of apomorphine.
• the 6,7-dihydroxy isomer is also said to be a presynaptic dopamine receptor agonist, according to Lander et al., Science
• This invention provides carboxamido-substituted hydroxyaminotetralins (or tetrahydronaphthalenes) of the formula ##STR1## wherein one of R and R 1 is H and the other is a carboxamido group, and R 2 and R 3 are individually H, methyl, ethyl or n-propyl; and pharmaceutically acceptable acid addition salts thereof.
• R and R 1 is H and the other is a carboxamido group
• R 2 and R 3 are individually H, methyl, ethyl or n-propyl
• pharmaceutically acceptable acid addition salts thereof are dopamine agonists and are therefore useful in inhibiting prolactin secretion, alleviating the symptoms of Parkinsonism and reducing blood pressure levels in mammals having elevated blood pressure.
• R is carboxamide and R 1 is H
• the compounds have the following formula ##STR2## and are named as dl(or ⁇ )-2-hydroxy-6-amino-5,6,7,8-tetrahydronaphthalene-1-carboxamides.
• R is H and R 1 is carboxamide
• the ring numbering is also changed and the compounds (Ib) ##STR3## are named as dl(or ⁇ )-3-hydroxy-7-amino-5,6,7,8-tetrahydronaphthalene-2-carboxamides.
• the "dl” refers to the fact that the carbon carrying the amine function is asymmetric, thereby giving rise to two optical isomers occurring as a racemic mixture.
• This invention includes within its scope dopamine agonists of formula I, whether as a racemate or as the d or l components thereof.
• intermediates useful in preparing the above compounds having the structure ##STR4## wherein one of R 4 and R 5 is H and the other is ##STR5## alkyl, or ##STR6## R 6 is H or benzyl and R 7 and R 8 are individually H, methyl, ethyl or n-propyl.
• Pharmaceutically-acceptable acid addition salts of the compounds of this invention include salts derived from non-toxic inorganic acids such as: hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydriodic acid, phosphorous acid and the like, as well as salts derived from nontoxic organic acids such as aliphatic mono and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic and alkandioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, etc.
• non-toxic inorganic acids such as: hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydriodic acid, phosphorous acid and the like
• nontoxic organic acids such as aliphatic mono and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic and alkandioic acids, aromatic acids
• Such pharmaceutically-acceptable salts thus include sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, fluoride, acetate, propionate, decanoate, caprylate, acrylate, formate, isobutyrate, caprate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, mandelate, butyne-1,4-dioate, hexyne-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, terephthalate, benzenesulfonate, toluenes
• the compounds of this invention are prepared, by chemically similar routes, the route depending on whether a compound according to Ia or Ib is desired. These routes are set forth in Reaction Schemes A-G below.
• routes are set forth in Reaction Schemes A-G below.
• compounds having a single mono-valent substituent [OH, N 3 , NH 2 , N(alk) 2 , etc.] in the tetrahydro portion of the tetrahydronaphthalene; e.g.
• asymmetric carbons are present at both C-5 and C-6 (in the 1-naphthoic acid series) or at C-7 and C-8 (in the 2-naphthoic acid series); e.g., IX, XIX, XX, XXIV, XXXII, XXXVII and XXXVIII.
• Compounds with two asymmetric centers exist as four stereoisomers, occurring as two racemic pairs.
• Formulas bearing the above numbers, while two dimensional, are intended to represent the 3-dimensional individual enantiomers as well as the optically neutral racemates, made up of molecular compounds each containing a pair of stereoisomers.
• a convenient preparation of compounds in which the carboxamide group is to be at C-7 begins with commercially available 3-hydroxy-2-naphthoic acid.
• the process of converting this compound to Ib is illustrated in the first part of Reaction Scheme A.
• the hydroxy acid is first converted to the corresponding methyl ester (III) according to the procedure of J.A.C.S., 76, 5761 (1954) utilizing dimethyl sulfate in the presence of potassium bicarbonate as the methylating system.
• Other esterification systems can be used as will be apparent to those skilled in the art, and other lower alkyl esters can be prepared and are equally useful.
• Reaction Scheme B gives the remainder of this first synthetic route.
• the reaction of the carbonyl compound (VI) with hydroxylamine hydrochloride produces the corresponding oxime (XVI).
• the oxime is next acylated with an aryl sulfonylchloride such as benzenesulfonylchloride or p-tosylchloride to yield the aryl sulfonyloxy derivative (XVII).
• This derivative upon treatment with a base such as potassium ethylate, rearranges to yield methyl dl-5,6,7,8-tetrahydro-3-benzyloxy-8-oxo-7-amino-2-naphthoate (XXVIII), isolated in the form of its hydrochloride salt.
• a base such as potassium ethylate
• Sodium borohydride reduction of the aminoketone yields the corresponding 8-hydroxy derivative (XIX).
• the amino group can be alkylated.
• the amine is reacted with at least 2 moles of propionaldehyde in the presence of sodium cyanoborohydride.
• methyl 5,6,7,8-tetrahydro-3-benzyloxy-8-oxo-2-naphthoate (VI) can be brominated alpha to the carbonyl group using pyridinium perbromide hydrobromide or other suitable brominating agent including molecular bromine to yield the corresponding 8-oxo-7-bromo derivative (VII).
• Reaction of this bromo derivative with sodium azide yields methyl dl-5,6,7,8-tetrahydro-3-benzyloxy-8-oxo-7-azido-2-naphthoate (VIII).
• Reduction with sodium borohydride serves to reduce the oxo group to a hydroxy group (IX) and the hydroxy is removed by treatment with triethylsilane in trifluoroacetic acid (TFA).
• TFA trifluoroacetic acid
• the resulting 7-azido derivative (X) is then converted to the corresponding 7-amino derivative (XII) by treatment with hydrazine and Raney nickel.
• the 7-amino derivative (XII) can be alkylated as with formaldehyde, acetaldehyde or propionaldehyde and sodium cyanoborohydride to yield the 7-N,N-dialkyl derivative (XIV), which derivative after debenzylation with hydrogen over a palladium catalyst followed by conversion of the ester to the amide yields an N,N-dialkyl-3-hydroxy-7-amino-5,6,7,8-tetrahydronaphthalene-2-carboxamide (Ib where R 2 and R 3 are individually methyl, ethyl or n-propyl. ##STR7## where R 10 is H, methyl or ethyl. ##STR8## where R 10 is H, methyl or ethyl.
• the hydroxyl group is readily removed by treatment with triethylsilane and trifluoroacetic acid to yield methyl dl-2-benzyloxy-6-azido-5,6,7,8-tetrahydro-1-naphthoate (XXV).
• the 6-azido group is then converted to an amino group by treatment with hydrazine and Raney nickel to provide the corresponding 6-amino derivative (XXVII).
• the amino derivative can then be alkylated by treatment with a lower alkyl aldehyde (formaldehyde, acetaldehyde, or propionaldehyde) and sodium cyanoborohydride.
• the resulting compound a methyl dl-2-benzyloxy-6-dialkyl-amino-5,6,7,8-tetrahydro-1-naphthoate (XXVIII), upon hydrogenation with palladium-on-carbon, is debenzylated to yield the corresponding 2-hydroxy compound (XXIX).
• the ester group is then converted with hydrazine to the carboxhydrazide derivative (XXX) which can be split by treatment with Raney nickel to yield a dl-2-hydroxy-6-dialkylamino-5,6,7,8-tetrahydronaphthalene-1-carboxamide (Ia).
• the 2-hydroxycarboxylic acid ester (XXIX) can be converted directly to the carboxamide (Ia) with methanolic ammonia under pressure.
• R 10 is H, Me or Et.
• the methyl 2 -benzyloxy-5-oxo derivative a precursor to the 6-bromo derivative used as a starting material in the above sequence
• the 5-hydroxy compound which can in turn be dehydrated to give a methyl 2-benzyloxy-7,8-dihydro-1-naphthoate (XXXI).
• XXXI methyl 2-benzyloxy-7,8-dihydro-1-naphthoate
• the same compound can be prepared from the 5-oxo-6-bromo derivative (XXII) by reduction of the carbonyl group to hydroxyl and removal of the elements of HOBr to yield the 5,6-unsaturated derivative (XXXI).
• the benzyloxy derivative can be alkylated with a lower aldehyde and sodium cyanoborohydride to yield a dl-2-benzyloxy-6-dialkylamino-5,6,7,8-tetrahydronaphthalene-1-carboxamide (XXXXI) which compound, upon treatment with hydrogen in the presence of a palladium catalyst, yields a compound of this invention (Ib) where R 2 and R 3 are individually Me, Et or n-Pr.
• Reaction Scheme G illustrates an alternative procedure for proceeding from an azido naphthoate ester with a protected ortho-benzyloxy group (here, the 1-naphthoate derivative XXV) to the dl-2-hydroxy-6-amino-1-naphthalenecarboxamide, via the free acid, acid chloride and amide followed by reduction of the azide group to NH 2 and lastly by debenzylation to the free 2-OH derivative.
• R 2 and R 3 H.
• the secondary amine thus produced after debenzylation and amidation, has a structure according to I wherein one of R and R 1 is H and the other is carboxamide, and one of R 2 and R 3 is H and the other is Me, Et or n-Pr.
• the aldehyde-cyanoborohydride procedure can thus be repeated, if desired, on the secondary amino compound with a different aldehyde so as to produce a compound according to I wherein R 2 and R 3 are not the same but are individually Me, Et or n-Pr.
• a solution was prepared by dissolving 8.9 g. of methyl 2-benzyloxy-5-oxo-5,6,7,8-tetrahydro-1-napthoate prepared by the procedure of Chem. Pharm. Bull., 25, 2999 (1977) in 150 ml. of methanol and 150 ml. of tetrahydrofuran (THF).
• THF tetrahydrofuran
• pyridinium perbromide hydrobromide were added and the reaction mixture stirred for about three hours, after which time it was diluted with water and the resulting aqueous mixture extracted with chloroform.
• the chloroform layer was separated and the separated layer washed with saturated sodium chloride and then dried.
• the compound melted at 65°-7° C. with decomposition after crystallization from methanol.
• the 6-azido compound was dissolved in about 200 ml. of methanol and the methanol solution cooled to about 0° C.
• Nine grams of sodium borohydride were added thereto in small portions with stirring.
• the reaction mixture was next stirred for about four hours and then diluted with water.
• the aqueous mixture was extracted several times with equal volumes of chloroform.
• the chloroform extracts were combined and the combined extracts washed with saturated sodium chloride and then dried. Evaporation of the chloroform yielded methyl dl-2-benzyloxy-5-hydroxy-6-azido-5,6,7,8-tetrahydronaphthoate formed in the above reaction.
• reaction mixture was filtered and the volatile constituents removed by evaporation. This residue was dissolved in 200 ml. of methanol. One gram of sodium cyanoborohydride was added followed by 10 ml. of 37% aqueous formaldehyde. The reaction mixture was stirred at room temperature under a nitrogen atmosphere overnight and was then diluted with saturated aqueous sodium bicarbonate. The alkaline aqueous mixture was extracted with chloroform. The chloroform extract was separated and the separated extract washed with saturated aqueous sodium chloride and then dried. Evaporation of the solvent yielded a residue which, by TLC, indicated one major product contaminated with a small amount of starting material.
• the solid hydrochloride salt obtained above was dissolved in water and dilute aqueous sodium bicarbonate added until the aqueous layer became basic. The aqueous layer was extracted several times with an equal volume of a chloroform/isopropanol solvent mixture. The organic extracts were combined and the combined extracts washed with saturated aqueous sodium chloride and then dried. Evaporation of the solvent in vacuo yielded 1.20 g. of an oil comprising methyl dl-2-hydroxy-6-dimethylamino-5,6,7,8-tetrahydro-1-naphthoate free base. The oil was dissolved in a 60 ml. of methanol to which was added 10 ml. of anhydrous hydrazine.
• the reaction mixture was heated to refluxing temperature for about one day and then cooled.
• the volatile constituents were removed in vacuo and the residue, comprising dl-2-hydroxy-6-dimethylamino-5,6,7,8-tetrahydro-1-naphthalenecarboxhydrazide formed in the above reaction, was dissolved in 125 ml. of ethanol to which were added about 2 g. of Raney nickel.
• This reaction mixture was heated to refluxing temperature for about one day after which time it was cooled and filtered. Gaseous HCl was passed into the solution.
• the volatile constituents were evaporated in vacuo and the residue recrystallized from ethanol.
• Four hundred and seventy mg. of dl-2-hydroxy-6-dimethylamino-5,6,7,8-tetrahydro-1-naphthalenecarboxamide hydrochloride were obtained melting at 249°-251° C. with decomposition.
• Example 2 Still following the procedure of Example 1, this compound was reacted with hydrazine hydrate and Raney nickel in THF and ethanol to yield methyl dl-2-benzyloxy-6-amino-5,6,7,8-tetrahydro-1-naphthoate.
• the 6-amino compound was dissolved in 200 ml. of methanol to which was added 1 g. of sodium cyanoborohydride followed by 10 ml. of propionaldehyde.
• the reaction mixture was stirred at room temperature under a nitrogen blanket overnight, and was then diluted with saturated aqueous sodium bicarbonate solution. The alkaline layer was extracted with chloroform.
• a reaction mixture was prepared from 200 g. of 3-hydroxy-2-naphthoic acid, 160 g. of potassium bicarbonate, 154 g. of dimethyl sulfate and 1500 ml. of acetone.
• the reaction mixture was heated to refluxing temperature for about 3 hours after which time it was diluted with water and the resulting alkaline aqueous layer extracted with ethyl acetate.
• the ethyl acetate layer was separated and the separated layer washed with water and saturated aqueous sodium chloride and then dried. Evaporation of the solvent yielded a residue which solidified upon trituration with methanol to yield 205 g. of methyl 3-hydroxy-2-naphthoate melting at 72°-4° C.
• a reaction mixture was prepared from the above quantity of ester, 50 g. of potassium carbonate 46 g. of benzylchloride and 400 ml. of dimethylacetamide (DMA). After the reaction had gone to completion, the reaction mixture was filtered through florisil and the precipitate of methyl 3-benzyloxy-5,6,7,8-tetrahydro-2-naphthoate which formed was crystallized from ethanol to yield 142.7 g. of compound melting at 60°-3° C.
• DMA dimethylacetamide
• the benzenesulfoximino compound was rearranged with alkali according to the following procedure: One and five tenths grams of methyl 3-benzyloxy-8-benzenesulfonyloximino-5,6,7,8-tetrahydro-2-naphthoate were dissolved in 40 ml. of toluene. This solution was added dropwise to a solution of potassium ethylate prepared by adding 0.2 g. of potassium to 25 ml. of ethanol. The reaction mixture was maintained in the range 0°-5° C. at which temperature it was stirred for about 1.5 hours after the addition had been completed.
• the reaction mixture was kept in the refrigerator for 48 hours after which time it was diluted with ethyl acetate and the separated ethyl acetate layer washed with water. The ethyl acetate layer was dried and the ethyl acetate removed by evaporation in vacuo. TLC showed one major spot.
• the residue was dissolved in methanol, and the hydrochloride salt was prepared by passing gaseous hydrogen chloride into a methanolic solution of the base. Recrystallization of the hydrochloride salt from a methanol/ether solvent mixture yielded 290 mg. of methyl dl-3-benzyloxy-7-amino-8-oxo-5,6,7,8-tetrahydro-2-naphthoate hydrochloride melting at 195°-200° C.
• a suspension of 2 g. of sodium borohydride was prepared in 100 ml. of ethanol. Two and two tenths grams of methyl dl-3-benzyloxy-7-amino-8-oxo-5,6,7,8-tetrahydro-2-naphthoate hydrochloride were added thereto in portions. The reaction mixture was stirred for two hours and was then diluted with water and the aqueous mixture extracted several times with equal volumes of chloroform. The chloroform extracts were combined and the combined extracts washed with saturated aqueous sodium chloride and then dried.
• the chloroform extracts were combined and the combined extracts washed with saturated aqueous sodium chloride and then dried. Evaporation of the solvent yielded methyl dl-3-hydroxy-7-di-n-propylamino-5,6,7,8-tetrahydro-2-naphthoate.
• the hydrochloride salt was prepared in ethanol solution, during which time a trans-esterification reaction apparently occurred since the product isolated was ethyl dl-3-hydroxy-7-di-n-propylamino-5,6,7,8-tetrahydro-2-naphthoate hydrochloride. Four hundred and ten mg. of the hydrochloride salt melting at 202°-4° C. were obtained after recrystallization from an ethanol/ether solvent mixture.
• the chloroform phases were combined and the combined phases washed with water and with saturated aqueous sodium chloride and were then dried. Evaporation of the chloroform yielded a dark viscous oil. Trituration of the oil with CHCl 3 yielded a solid which was filtered and the filter cake dissolved in chloroform. The chloroform solution was chromatographed over 100 g. of florisil using chloroform containing increasing amounts (0-2%) of methanol as the eluant.
• a solution was prepared by dissolving 0.7 g. of dl-2-benzyloxy-6-azido-5,6,7,8-tetrahydro-1-naphthalenecarboxamide in 50 ml. of ethanol.
• the solution was placed in a low pressure hydrogenation apparatus and hydrogenated over a palladium-on-carbon catalyst at about 60 psi. After the theoretical quantity of hydrogen had been absorbed, the hydrogenation mixture was removed from the apparatus and the catalyst separated by filtration. Evaporation of the solvent from the filtrate yielded dl-2-hydroxy-6-amino-5,6,7,8-tetrahydro-1-naphthalenecarboxamide.
• a solution was prepared from 3.4 g. of dl-2-benzyloxy-6-azido-5,6,7,8-tetrahydro-1-naphthalenecarboxamide (from Example 4) and 100 ml. of isopropanol. The solution was cooled and 0.5 g. sodium borohydride added thereto in small portions. After the addition had been completed, the reaction mixture was heated to reflux temperature under a nitrogen blanket for about 18 hours. The reaction mixture was then cooled and the cooled mixture diluted with water. The aqueous mixture was made acidic by the addition of 1 N aqueous hydrochloric acid. The aqueous acidic layer was extracted with ether and the ether extract discarded.
• the aqueous acidic layer was made basic by the addition of 10% aqueous sodium hydroxide.
• the alkaline layer was extracted several times with equal volumes of a 3:1 chloroform/methanol solvent mixture.
• the organic extracts were combined and the combined extracts washed with saturated aqueous sodium chloride and then dried. Evaporation of the solvent therefrom yielded a residue comprising dl-2-benzyloxy-6-amino-5,6,7,8-tetrahydro-1-naphthalenecarboxamide.
• TLC indicated a single spot at the origin.
• An infrared spectrum of the solid indicated no absorption attributable to an azide group.
• the residue was dissolved in chloroform and the chloroform solution saturated with gaseous hydrogen chloride.
• Yield of dl-2-benzyloxy-6-amino-5,6,7,8-tetrahydro-1-naphthalenecarboxamide was 0.46 g. (100%).
• This 0.46 g. sample was alkylated with propionaldehyde and sodium cyanoborohydride by the procedure of Example 1 to yield dl-2-benzyloxy-6-di-n-propylamino-5,6,7,8-tetrahydro-1-naphthalenecarboxamide hydrochloride.
• the hydrochloride salt was converted back to the free base by standard procedures and the free base chromatographed. Fractions containing dl-2-hydroxy-6-di-n-propylamino-5,6,7,8-tetrahydro-1-naphthalenecarboxamide were combined and the solvent removed by evaporation. The solid was reconverted to the hydrochloride salt in ethanol with gaseous hydrogen chloride. Ether was added to the ethanol solution to the point of incipient precipitation and the solution cooled to about -15° C.
• a solution was prepared from about 10 g. of methyl 2-benzyloxy-5-oxo-5,6,7,8-tetrahydro-1-napthoate in 250 ml. of methanol to which was added 10 g. of sodium borohydride in small portions with cooling. After the borohydride had been added, the mixture was stirred for about 3 hours and then diluted with water. The aqueous layer was extracted several times with equal volumes of chloroform. The chloroform extracts were combined and the combined extracts were washed with saturated aqueous sodium chloride and then dried. Evaporation of the solvent yielded 7.0 g. of an oil comprising methyl dl-2-benzyloxy-5-hydroxy-5,6,7,8-tetrahydro-1-naphthoate.
• Methyl 2-benzyloxy-5-oxo-5,6,7,8-tetrahydro-1-naphthoate was brominated with pyridinium bromide perbromide in glacial acetic acid.
• Methyl dl-2-benzyloxy-5-oxo-6-bromo-5,6,7,8-tetrahydro-1-naphthoate melting at 120°-4° C. was obtained.
• Twenty-six grams of the bromo ketone were suspended in 600 ml. of methanol and 20 g. of sodium borohydride added.
• a reaction mixture was prepared from 6.5 g. of methyl 2-benzyloxy-7,8-dihydro-1-naphthoate, 4.8 g. of 85% m-chloroperbenzoic acid, 250 ml. of chloroform and 25 ml. of anhydrous ethanol. The reaction mixture was allowed to remain overnight at ambient temperature. Evaporation of the volatile constituents in vacuo left a residue which was dissolved in chloroform. The chloroform solution was filtered through about 150 g. of alumina (grade I).
• hydrochloride salt was converted to the free base by standard procedures. Sixty-four hundredths grams of free base thus obtained were dissolved in boiling methanol to which was added 280 mg. of oxalic acid dihydrate. Six hundred milligrams of the oxalate salt of methyl dl-2-benzyloxy-6-amino-5,6,7,8-tetrahydro-1-naphthoate melting at 181°-3° C. were obtained.
• the primary amine thus prepared can be debenzylated by hydrogenation over a palladium-on-carbon catalyst and the resulting compound converted to the carboxamide by procedures set forth in the above examples.
• the amine can be alkylated with formaldehyde, acetaldehyde or propionaldehyde in the presence of sodium cyanoborohydride and the resulting dialkylamine debenzylated and the free-hydroxy compound converted to the carboxamide also by procedures of the above examples.
• the chloroform extract containing methyl dl-3-benzyloxy-7-bromo-8-oxo-5,6,7,8-tetrahydro-2-naphthoate was washed with saturated aqueous sodium chloride and then dried. The solvent was removed therefrom by evaporation. The resulting residue was dissolved in 500 ml. of DMF containing 10 ml. of glacial acetic acid. The solution was cooled in an ice-water bath to about 0° C. A solution of 12 g. of sodium azide in 100 ml. of water was added. The reaction mixture was cooled for 2 hours, and was then diluted with water. The aqueous mixture extracted with ethyl acetate.
• the ethyl acetate extract was washed with water and with saturated aqueous sodium chloride and was then dried. Evaporation of the ethyl acetate yielded a residue comprising methyl dl-3-benzyloxy-7-azido-8-oxo-5,6,7,8-tetrahydro-2-naphthoate.
• the residue was dissolved in THF and the THF solution diluted with 400 ml. of methanol.
• the solution was cooled to about 0° C. and 20 g. of sodium borohydride added thereto in portions.
• the reaction mixture was stirred at ambient temperature for about 2 hours and was then diluted with water, and the resulting aqueous mixture extracted with chloroform.
• the chloroform layer was separated; the separated layer washed with water and with saturated aqueous sodium chloride and then dried. Evaporation of the chloroform yielded methyl dl-3-benzyloxy-7-azido-8-hydroxy-5,6,7,8-tetrahydro-2-naphthoate. This residue was chromatographed over 400 g. of florisil using hexane containing increasing amounts (0-100%) ether as the eluant. Twenty grams of the hydroxy azide were obtained from fractions shown by TLC to contain the desired material.
• aqueous layer and acidic extracts were then made basic with 14 N ammonium hydroxide and the basic layer extracted with chloroform.
• the chloroform extract was separated and the separated extract washed with saturated aqueous sodium chloride and then dried. Evaporation of the solvent yielded 15.5 g. of methyl dl-3-benzyloxy-7-amino-5,6,7,8-tetrahydro-2-naphthoate.
• a portion of the above free base was converted to the hydrochloride salt. Eight and nine tenths grams of this salt were dissolved in methanol containing 1 ml. of water. Two grams of 5% palladium-on-carbon were added and the mixture hydrogenated at 60 psi. The hydrogenation mixture was then filtered and the filrate evaporated to dryness in vacuo. A white solid shown by TLC to consist of a single spot comprising methyl dl-3-hydroxy-7-amino-5,6,7,8-tetrahydro-2-naphthoate hydrochloride was obtained. This white solid was dissolved in methanol and the methanol solution cooled to about 0° C.
• the compounds of this invention are dopamine agonists.
• one of their properties, shared by many dopamine agonists, is the ability to lower blood pressure in anesthetized spontaneously hypertensive rats (SHR).
• SHR spontaneously hypertensive rats
• Table 1 which follows gives the results of testing compounds of this invention which lowered the blood pressure of anesthetized SHR at dose levels of 1 mg./kg. or lower.
• the first 4 columns give the substitution pattern of the hydroxyaminonaphthalene carboxamide and the second 4 columns the percent blood pressure lowering ⁇ standard error for the particular compound at 4 different dose levels.
• the compounds of this invention are also useful as inhibitors of prolactin secretion.
• Dopaminergic drugs with such activity can be employed in the treatment of inappropriate lactation, such as post-partum lactation and galactorrhea.
• the compounds of this invention have been shown to inhibit prolactin secretion according to the following procedure:
• Adult male rats of the Sprague-Dawley strain weighing about 200 g. were housed in an air-conditioned room with controlled lighting (lights on 6 a.m.-8 p.m.) and fed lab chow and water ad libitum.
• Each rat received an intraperitoneal injection of 2.0 mg. of reserpine in aqueous suspension 18 hours before administration of the test compound.
• the purpose of the reserpine was to keep prolactin levels uniformly elevated.
• the compounds under test were dissolved in water and were injected intraperitoneally at a 1 mg./kg. dose level. Each compound was administered to a group of 10 rats, and a control group of 10 intact males received an equivalent amount of solvent only. One hour after treatment all rats were killed by decapitation, and 150 ⁇ l. aliquots of serum were assayed for prolactin.
• a compound according to Formula I, above, or a salt thereof with a pharmaceutically-acceptable acid is administered to a subject suffering from Parkinsonism or hypertension, or needing to have his or her prolactin level reduced, in an amount effective to alleviate some of the symptoms of Parkinsonism or to reduce blood pressure or to reduce an elevated prolactin level.
• Oral administration is preferred. If parenteral administration is used, administration is preferably by the subcutaneous route using an appropriate pharmaceutical formulation. Other modes of parenteral administration such as intraperitoneal, intramuscular, or intravenous routes are equally effective.
• a water soluble pharmaceutically-acceptable salt is employed.
• a compound according to Formula I either as the free base or in the form of a salt thereof, is mixed with standard pharmaceutical excipients and the mixture loaded into empty telescoping gelatin capsules or pressed into tablets.
• the oral dosage should be in the range 0.01-10 mg./kg. of mammalian body weight and the parenteral dose in the range 0.0025 to 2.5 mg./kg.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Public Health (AREA)
• General Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Veterinary Medicine (AREA)
• Pharmacology & Pharmacy (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Cardiology (AREA)
• Heart & Thoracic Surgery (AREA)
• Biomedical Technology (AREA)
• Neurology (AREA)
• Neurosurgery (AREA)
• Materials Engineering (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Priority Applications (12)

Applications Claiming Priority (1)

Related Child Applications (1)

Publications (1)

Family

ID=23755442

Family Applications (1)

Country Status (11)

Cited By (5)

Families Citing this family (3)

Citations (2)

Family Cites Families (2)

• 1982
  • 1982-11-16 US US06/442,074 patent/US4448990A/en not_active Expired - Fee Related
• 1983
  • 1983-11-07 IL IL70158A patent/IL70158A/xx unknown
  • 1983-11-10 GR GR72940A patent/GR79034B/el unknown
  • 1983-11-10 CA CA000440888A patent/CA1198122A/en not_active Expired
  • 1983-11-11 DK DK5154/83A patent/DK515483D0/da unknown
  • 1983-11-14 DE DE8383306936T patent/DE3363813D1/de not_active Expired
  • 1983-11-14 EP EP83306936A patent/EP0109815B1/de not_active Expired
  • 1983-11-14 GB GB08330279A patent/GB2130209B/en not_active Expired
  • 1983-11-15 JP JP58215891A patent/JPS59108748A/ja active Pending
  • 1983-11-15 HU HU833927A patent/HU196168B/hu unknown
  • 1983-11-16 KR KR1019830005431A patent/KR870000204B1/ko active IP Right Grant

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events